Intelligent RFID tag for magnetic field mapping

ABSTRACT

System(s) and method(s) to increase the accuracy and efficiency of an RFID system is provided. A system includes an RFID component that receives a signal from an RFID reader, and an identifier component that interfaces with the RFID component and identifies the source of the signal. The system further includes a signal strength component that interfaces with the identifier component and measures the strength of the signal. The system can include an environment component that analyzes an operating environment.

CLAIM OF PRIORITY UNDER 35 U.S.C. §120

The present Application for Patent is a continuation of patentapplication Ser. No. 11/235,730 entitled “INTELLIGENT RFID TAG FORMAGNETIC FIELD MAPPING” filed Sep. 26, 2005, and issuing on Nov. 4,2008, as U.S. Pat. No. 7,446,662, and assigned to the assignee hereofand hereby expressly incorporated by reference herein.

TECHNICAL FIELD

The following description relates generally to radio frequencyidentification (RFID) systems and more specifically, to systems andmethods that improve accuracy and increase efficiency of RFID systems.

BACKGROUND OF THE INVENTION

Radio Frequency Identification (RFID) technology leverages electronicdata and wireless communication for identification purposes. With RFIDsystems, electronic data typically is stored within an RFID tag, whichcan be formed from a small silicon chip and one or more antennas, andaffixed to a product. Reading from and/or writing to an RFID tag can beachieved through radio frequency (RF) based wireless communication viadevices referred to as RFID readers. In general, writing is utilized toadd and/or modify product-specific information to an RFID tag, andreading is utilized to retrieve the information, for example, to providefor automatic product identification. In many instances, the electronicdata written to and/or read from an RFID tag includes an ElectronicProduct Code (EPC), which, in general, is a unique number that isencoded (e.g., as a bit code) and embedded within the RFID tag. TypicalEPC data can include information about the associated product (e.g.,product type, date of manufacture, lot number, . . . ) and/or associatedpallets, boxes, cases and/or container levels, for example.

When passed through or scanned by a reader, an RFID tag emits storedelectronic data such that the data can be retrieved by an RFID readerwithout unpacking the product or scanning barcode labels. Readinformation can be utilized to provide a greater degree of certaintyover what goes into a supply chain and/or how to manage raw materials,warehouse inventory, shipments, logistics, and/or various other aspectsof manufacturing.

One of the challenges associated with applying RFID technology is theuncertainty of whether an RFID reader antenna(s) cover thereading/writing area of a given RFID target. Since the magnetic field ofan antenna is not visible, the coverage area is generally roughlyestimated when positioning the antenna and it is difficult to determineand measure the signal strength without expensive tools (e.g.,spectrometer equipment). Additional challenges are associated withpallet applications where there is a need to read multiple (e.g., 100 ormore) RFID tags at substantially the same time. Some of the tags may beburied in the middle of a pallet with no way to physically access thetag without removing the other products on the pallet. Without a meansto measure the strength of the magnetic field it is unknown if all theRFID tags on the pallet are being read. Accordingly, there is an unmetneed in the art for an improved RFID system to increase system accuracyand efficiency.

SUMMARY OF THE INVENTION

The following presents a simplified summary of the invention in order toprovide a basic understanding of some aspects of the invention. Thissummary is not an extensive overview and it is not intended to identifykey/critical elements or to delineate the scope of the invention. Itssole purpose is to present some concepts in a simplified form as aprelude to the more detailed description that is presented later.

The invention disclosed and claimed herein, in one aspect thereof,comprises an RFID system that includes an RFID component, which receivesa signal from an RFID reader, and an identifier component thatinterfaces with the RFID component and identifies the source of thesignal. The system further includes a signal strength component thatinterfaces with the identifier component and measures the strength ofthe signal. Further included is a signal measurement component at theRFID reader that measures a voltage level associated with a signalreceived from the RFID tag.

According to another aspect thereof, a methodology of improving RFIDaccuracy is disclosed. The method includes receiving a signal from anRFID reader, analyzing a parameter associated with the signal, andmapping a magnetic field based at least in part on the parameter. Themethod can further include adjusting a signal strength based upon theparameter and/or the mapped magnetic field.

To the accomplishment of the foregoing and related ends, certainillustrative aspects of the invention are described herein in connectionwith the following description and the annexed drawings. These aspectsare indicative, however, of but a few of the various ways in which theprinciples of the invention can be employed and the subject disclosureis intended to include all such aspects and their equivalents. Otheradvantages and novel features will become apparent from the followingdetailed description of the invention when considered in conjunctionwith the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an intelligent RFID tag in accordance with thesubject invention.

FIG. 2 illustrates a more detailed diagram of an implementation of thetag IC of FIG. 1, in accordance with the invention.

FIG. 3 illustrates an exemplary RFID data packet that includes signalstrength data which can be communicated in accordance with theinvention.

FIG. 4 illustrates an RFID (Radio Frequency Identification) system inaccordance with the subject invention.

FIG. 5 illustrates an RFID system in accordance with another aspect ofthe invention.

FIG. 6 illustrates an RFID system that employs collection and mappingtechniques to improve system accuracy.

FIG. 7 illustrates an RFID system that monitors an external and/orinternal operating environment.

FIG. 8 illustrates an application of an RFID system in accordance withat least one aspect of the invention.

FIG. 9 is a methodology for optimizing the performance of an RFIDsystem.

FIG. 10 illustrates a methodology for utilizing an intelligent RFID tagto obtain signal strength and environment information.

FIG. 11 illustrates a block diagram of a computer operable to executethe disclosed architecture.

FIG. 12 illustrates a schematic block diagram of an exemplary computingenvironment in accordance with the subject invention.

DESCRIPTION OF THE INVENTION

The invention is now described with reference to the drawings, whereinlike reference numerals are used to refer to like elements throughout.In the following description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the subject invention. It may be evident, however, thatthe invention can be practiced without these specific details. In otherinstances, well-known structures and devices are shown in block diagramform in order to facilitate describing the invention.

As used in this application, the terms “component” and “system” areintended to refer to a computer-related entity, either hardware, acombination of hardware and software, software, or software inexecution. For example, a component can be, but is not limited to being,a process running on a processor, a processor, a hard disk drive,multiple storage drives (of optical and/or magnetic storage medium), anobject, an executable, a thread of execution, a program, and/or acomputer. By way of illustration, both an application running on aserver and the server can be a component. One or more components canreside within a process and/or thread of execution, and a component canbe localized on one computer and/or distributed between two or morecomputers.

As used herein, the terms “infer” and “inference” refer generally to theprocess of reasoning about or inferring states of the system, and/orenvironment from a set of observations as captured via events and/ordata. Inference can be employed to identify a specific context oraction, or can generate a probability distribution over states, forexample. The inference can be probabilistic—that is, the computation ofa probability distribution over states of interest based on aconsideration of data and events. Inference can also refer to techniquesemployed for composing higher-level events from a set of events and/ordata. Such inference results in the construction of new events oractions from a set of observed events and/or stored event data, whetheror not the events are correlated in close temporal proximity, andwhether the events and data come from one or several event and datasources.

FIG. 1 illustrates an intelligent RFID tag 100 in accordance with thesubject invention. The tag 100 can include a single antenna 102 (ormultiple antennas) (denoted ANTENNA) that facilitates communicatingsignals and data with an RFID reader (or reader/writer) (not shown). Thetag 100 also includes a tag IC 104 that provides onboard processing ofthe data and signals. In support thereof, the tag IC 104 furtherincludes a processor 106 (e.g., a digital signal processor-DSP) thatfacilitates data and signal processing and storage, and a transceiver108 that interfaces to the antenna 102 for communications of the dataand signals. The tag 100 can be an active tag, such that a power source110 (e.g., a coin cell, capacitor) is provided. Alternatively, the tag100 is passive, whereby the power source 110 is not provided.

The tag 100 is capable of operating in a multi-frequency bandenvironment such that a first set of readers operate on a firstfrequency band and a second set of readers operate on a second frequencyband. Accordingly, FIG. 2 illustrates a more detailed diagram of animplementation of the tag IC 104 of FIG. 1, in accordance with theinvention. The tag IC 104 includes the transceiver 108 that interfacesthe antenna 102 (of FIG. 1) to the processor 106. The transceiver 108also interfaces to a signal detection and strength processing block 200that facilitates signal strength processing onboard the tag IC 104 inaccordance with the invention. The block 200 interfaces to the processor106 such that multi-band data and signal processing can be performed.Accordingly, when a reader transmits a signal, the tag IC 104 receivesthe signal via the transceiver 108 into the signal detection andstrength processing block 200, wherein the signal frequency isdiscriminated and processed for signal strength data. Additionally, asdescribed above, the signal can include reader identification (ID) datathat uniquely identifies the reader. Thus, once the signal strength data(or environmental data such as temperature, pressure, vibration, etc.)is computed, the signal strength (or other) data and the reader ID datacan be stored on the tag IC 104 in a memory 202, and/or transmitted viathe transceiver 108 to an external system (e.g., the reader and/or acontroller), which is not shown. As multiple tags respond, the field canbe mapped for a given area. The tag IC 104 can also include an optionalonboard power source 204 that provides power in an active transpondertag implementation.

FIG. 3 illustrates an exemplary RFID data packet 300 that includessignal strength data which can be communicated in accordance with theinvention. The packet 300 can include a tag ID 302 that uniquelyidentifies the tag; however, this is not a requirement. Product data 304is included that describes the product to which the RFID tag is attachedor associated. The packet 300 can also include signal strength data 306that was computed on the tag for a given reader. Frequency data 308 canalso be provided the identifies the frequency (or frequency band, e.g.,about a 915 MHz band) on which the associated signal strength data wascalculated; however, this is not required, since reader ID data 310 canbe received from the reader from which the generated frequency can beknown. Environmental data 312 can also be communicated, since the tag ICcan interface to one or more environmental sensors (e.g., temperature,pressure, humidity, shock, vibration, . . . ). Other data can also becommunicated via the packet 300, according to the particularapplication.

FIG. 4 illustrates an RFID (radio frequency identification) system 400that manages electronic product information (or data) within anindustrial control system. The system 400 includes an RFID detectioncomponent 402 that interfaces with a RFID component 404 via wirelesscommunications. The RFID detection component 402 can be variouscomponents that read, write, receive, and/or store electronic productdata, such as, readers, writers and/or servers, and can be a handhelddevice or a fixed-mount device depending on the particular application.The RFID detection component 402 can broadcast a signal or radio wavesvia an antenna or a plurality of antennas (not shown). The antenna for aparticular device may be of various types suitable for use in a wirelesscommunications system, such as a dipole antenna, a yagi-type antenna,etc. The coverage area 408 or signal range of the RFID detectioncomponent 402 can be anywhere from about one inch to about one hundredfeet or more, depending upon the radio frequency used and the poweroutput. The frequency range of the RFID system 400 can be alow-frequency range (e.g., from about 30 KHz to about 500 KHz), anintermediate-frequency range (e.g., about 10 MHz to about 15 MHz) or ahigh-frequency range, (e.g., from about 850 MHz to about 950 MHz andabout 2.4 GHz to about 2.5 GHz). Higher frequency ranges offer longerread ranges (e.g., about 90 feet or more) and higher reading speeds. Thesignal can be continuously transmitted or periodically transmitted, suchas when activated by a sensor device.

The RFID detection component 402 is operative to transmit a signal tothe RFID component 404 and vice versa. Upon receiving the signal, theRFID component 404 transmits a reply signal that is sent to and receivedby the RFID detection component 402. The RFID component 404 can be anactive or passive RFID tag. The bi-directional signal transmissionoperates in similar manner for both passive and active tags. Active RFIDtags contain an internal battery or other suitable power source and aretypically read/write devices. That is to say, the tag data can berewritten and/or modified. The memory size of an active tag can varydepending on the application requirements and, since it is poweredonboard, it generally has a longer or wider read range or coverage areathan a passive tag. Passive tags do not typically have an internal powersource and obtain power generated by a reader. Passive tags can beread/write devices or read-only devices. A read-only tag is generallyprogrammed with a unique set of data that, in one implementation, cannotbe modified, and in another implementation, can be modified. Adifference between an active device and a passive device is the signalrange. Passive tags can be limited to a few meters because the RFIDdetection component 402 supplies the power to the tag via RF and is theonly power supplied to the tag. Active tags can be read over hundreds ofmeters because they have an internal power supply. An example of apassive tag is a tag on a box of detergent in a department store. Anactive tag can be utilized, for example, at toll booths on the turnpiketo determine which car is passing through the booth for later billingpurposes.

At about a substantially similar time as the RFID component 404 isactivated through the magnetic field of an antenna of the RFID detectioncomponent 402, the RFID measures its field strength by measuring thevoltage received from the RF field from the RFID detection component402. The RFID component 404 adds the voltage value to the end of the tagdata as extra data that it will send to the RFID detection component402.

The RFID detection component 402 transmits a signal that specifies arange of tags to respond. Only the tags within this range shouldrespond. If multiple tags respond, the RFID detection component 402 canspecify a shorter range until the desired tag or number of tags respond.The RFID detection component 402 cycles through the sequence looking foradditional tags.

The RFID component 404 can also provide a means to measure the strengthof the received signal. Transmitting data between the RFID detectioncomponent 402 and the RFID component 404 is subject to obstructions andinfluences on the transmitting media, e.g., air interference. Noiseinterference and distortion arise frequently and should be mitigated toachieve virtually error free data recovery. By measuring and recordingthe signal strength not only can the range of the RFID detectioncomponent 402 be determined but also obstructions which are interferingwith the signal can be located especially when there is an observedchange in the signal strength. There are at least two signal strengthmeasurements; the signal strength at the RFID component 404 and thesignal strength at the RFID detection component 402. Additional criteriathat can affect the signal can also be measured, analyzed, and/orrecorded such as environmental data.

Analysis of the data can indicate if a physical adjustment of theantenna(s) 406 is required to improve the efficiency and/or accuracy ofthe system 400. Analysis can also determine if there should be anelectronic adjustment of the signal strength of the antennas/readers forthe given RFID reading area. This process can be repeated after eachadjustment to facilitate configuration improvement in the coverage ofthe RFID antennas and the entire system 400.

With reference now to FIG. 5, illustrated is an RFID system 500 thatincludes an RFID read/write (R/W) component 502 operatively interfacedwith an RFID component 504 that includes an identifier component 506 anda signal strength component 508. The RFID R/W component 502 can includea signal measurement component 510. While only one RFID R/W component502 and one RFID component 504 are illustrated, it is to be appreciatedthat more than one of either or both components can be utilized inaccordance with the invention. It is also to be appreciated that whilethe combined functionality of an RFID R/W provides a more robustimplementation, the system 500 can employ strictly an RFID reader orstrictly an RFID writer without departing from the scope of theinvention.

The RFID R/W component 502 emits a radio signal via an antenna (notshown) to activate and/or read and/or write data to the RFID component504. The antenna can be of a size and/or shape suitable for the desiredapplication, and there may be more than one antenna operativelyassociated with the RFID R/W component 502. Radio waves in the RFIDsystem 500 can range anywhere from about one inch to about one hundredfeet or more, depending upon the power output of the RFID R/W component502, the radio frequency, and operating conditions (e.g., physicalobstructions, weather, . . . ).

When the RFID component 504 passes through the electromagnetic field ofthe RFID R/W component 502, an antenna (not shown) associated with theRFID component 504 receives the RFID R/W component 502 activationsignal. An identifier component 506, associated with the RFID component504, is able to identify the particular RFID R/W component 502 fromwhich the signal was broadcast. For example, the RFID R/W component 502may broadcast a signal with identifying data, such as a uniqueidentifier. The identifier component 506 is capable of associating thereceived signal with the exact RFID R/W 502 that sent the signal based,at least in part, on the unique identifier.

The RFID component 504 further includes a signal strength component 508that measures the strength of a received signal. The signal strength canbe determined by measuring the voltage received from the RF fieldgenerated by the RFID R/W component 502. The measured voltage is added,generally at the end, to the tag data as extra information. Amalgamatingthe signal information with information of the identifier component 506links the signal with a specific RFID R/W component 502. The RFID R/Wcomponent 502 includes a signal measurement component 510 that isconfigured to measure the strength of the signal received from the RFIDcomponent 504.

By way of example and not limitation, three detection components receivea signal from a single R/W reader. A first detection component receivesa strong signal, a second detection component receives a weak signal,and a third detection component receives a moderate strength signal. Bymapping the location of the respective detection components andidentifying the specific RFID R/W reader that sent the signalcorresponding reading areas can be ascertained, and problems regardingantenna orientation and/or obstructions in the reading area can bemitigated through further system processing. This information canfurther be utilized to determine where an RFID component is in relationto the R/W reader, such as which RFID component is the closest to theR/W reader.

FIG. 6 illustrates an RFID system 600 that employs collection andmapping techniques that improve system accuracy and efficiency. Thesystem 600 includes an RFID detection component 602 that emits a signal,and an RFID component 604 that receives the emitted signal viarespective antennas (not shown). The RFID component 604 includes acollection component 606 that interfaces with a mapping component 608and an adjustment component 610.

The RFID detection component 602 transmits a signal requesting RFIDcomponent 604 information. The RFID detection component 602 can be anRFID reader, and RFID writer, or an RFID reader/writer. The signal sentto the RFID component 604 has an associated identifier by which the RFIDdetection component 602 can be identified. The identifier can be aunique name, a number such as a serial number and/or unique componentnumber, or any type of information that can be transmitted wirelessly toallow recognition and identification. At a substantially similar time asthe emitted signal is received by an antenna operatively coupled to theRFID component 604, information associated with that signal is collectedby the collection component 606. For example, the collection component606 can detect, measure, calculate, and/or receive data associated withthe source of the emitted signal based at least in part on theassociated identifier.

The collection component 606 can further measure, calculate, detect,and/or receive information regarding the strength of the received signaland its associated RFID detection component 602. The strength of thesignal is an indication of the reading range of the RFID detectioncomponent 602. The field or range of the signal or radio wave deliveredby the RFID detection component 602 extends into the space surroundingit and the strength of the wave diminishes with respect to distance.That is to say, the greater the distance between the RFID detectioncomponent 602 and the RFID component 604, the weaker the signal strengthreceived by the RFID component 604. The antenna design determines theshape of the field or wave delivered, and the range is also influencedby the angle between the RFID detection component 602 and the RFIDcomponent 604. If there are no obstructions or mechanisms that absorbthe signal, the strength of the field is reduced in inverse proportionto the square of the distance that it travels.

At higher frequencies the absorption of the signal due to moisture, forexample, influences the range. For example, at 13.56 MHz the signal isnot absorbed by water (moisture) or human tissue. However, it will beunderstood by those having ordinary skill in the art that the subjectdisclosure works equally well at any frequency range including the EPC900 MHz Class 0 RFID Tag Specification which operates about a 900 MHzband, an 860-930 MHz Class 1 RFID tag RF and Logical CommunicationInterface Specification, and a 13.56 MHz ISM Band Class 1 RFID TagInterface Specification. It is to be understood that other frequencyranges, including yet to be defined RFID (EPC) standards, can workequally well with the embodiments disclosed herein. Through analysis ofboth the specific RFID detection component 602 that sent the signal andthe signal strength as received by the RFID component 604 modificationscan be made to increase the accuracy and coverage area of the system600.

The collection component 606 interfaces with the mapping component 608that facilitates determination of the RFID reading area. The mappingcomponent 608 obtains and/or calculates a location of the RFID component604 and using this information together with information received fromthe collection component 606 can map a reading area of the RFIDdetection component 602. Based upon the mapped reading area, theadjustment component 610 that interfaces with the mapping component 608can recommend a physical adjustment to an antenna, or it mayautonomously adjust the antenna. The adjustment component 610 canfurther electronically adjust the signal strength of theantennas/readers to the given RFID reading area. If any adjustments areperformed, the process can be repeated to introduce furthermodifications that improve the accuracy and efficiency of the RFIDsystem 600.

FIG. 7 illustrates another embodiment of an RFID system 700 wherein theoperating environment of the system and signal strength is analyzed. Thestrength and accuracy of the system is a component of the signalreaching its intended destination with sufficient strength to bedetected. Many obstructions and/or operating conditions (both internaland external) can influence the accuracy and performance of the RFIDsystem 700 and thus can be monitored, considered, and taken into accountto ensure the highest and most accurate system 700 performance.

The system 700 includes an RFID R/W component 702 that interfaces withan RFID component 704. The RFID component 704 includes an identifiercomponent 706 that identifies which RFID R/W component 702 signal wasreceived and a signal strength component 708 that measures the strengthof the received signal and includes the measured signal as extra dataincluded in the response signal returned to the RFID R/W component 702.The RFID component 704 further includes an environment component 710that measures, senses, calculates and/or determines an operatingenvironment and/or operating condition(s) of the system 700. Theenvironment component 710 can track internal, as well as externalconditions of the system 700, including controllable conditions (e.g.,antenna orientation) and uncontrollable conditions (e.g., weather). Theenvironment component 710 can include a plurality of modules that recordinformation at substantially the same time as a signal is received ordetected by the RFID component 704.

By way of example and not limitation, two uncontrollable conditionsinclude air temperature and humidity. Thus, the RFID component 704 caninclude a temperature module 712 that records the air temperature and ahumidity module 714 that detections the presence or absence of water inthe surrounding air space. Both the temperature information and thehumidity information can be taken into account when the reading area ofthe RFID R/W component 702 is mapped because these uncontrollableinfluences will affect the transmission signal and may be the cause ofsignal interferences.

Illustrations of potentially controllable influences that can bemonitored by the environment component 710 includes shock and vibrationvia a shock module 716 and a vibration module 718. As a product and itsassociated RFID tag is moved manually, automatically, by conveyor, etc.,the RFID tag moves in and out of reading areas of respective RFID R/Wcomponents. Due to the movement there is some vibration associated withthe product; however, too much vibration and/or shock may indicatesystem 700 problems.

Another example is if products are being moved via a conveyor belt andthe shock module 716 detects a sudden and/or large movement of theproduct it may indicate a problem unrelated to the RFID system. Shock,excessive vibration and/or large movement of the products may indicatewear and/or failures associated with the mechanical components of theconveyor such as motor(s), transmission(s), roller(s), etc. In such away, entire system failures can be diagnosed and corrected before amajor catastrophe. The vibration module 718 can detect normal vibrationas well as excessive vibration that indicate problems associated withthe movement of the product(s). If the vibration module 718 detects thatall vibration has ceased, but the part is still in a movement phase, theRFID component 704 can transmit a notification signal that there may bea problem with the system 700.

The additional components or sensors included on the RFID component 704can detect the environment around the RFID tag in addition to measuringsignal strength. By way of illustration and not limitation, the RFIDcomponent 704 can be on a box that contains frozen food. It is importantto maintain the temperature of the food below the freezing point. Thus,the temperature can easily be collected and communicated. If thetemperature was ever at a level above freezing, it can be readilydetermined and the frozen food can be removed, discarded, or processedin any manner desired.

The information measured, received or obtained by the RFID tag is addedto the tag data and transmitted to the RFID R/W component 702. A signalmeasurement component 720 of the RFID R/W component 702 measures thesignal received from the RFID component 704 to determine a magneticfield.

FIG. 8 illustrates an application of an RFID system in accordance withat least one aspect of the invention. A plurality of RFID R/W devices (afirst reader 802, a second reader 804, and a third reader 806) areemployed to detect the presence of a plurality of RFID tags. While theRFID devices (802, 804, and 806) are shown as overhead devices, itshould be understood that the devices can be located anywhere, providedthe range of coverage is appropriate for the particular purpose. Forexample, the devices (802, 804, and 806) can be underneath, on the sideand or in various locations throughout the environment. Each of the RFIDR/W devices (802, 804, and 806) transmits respective signals (808, 810,and 812) that can be constant, intermittent, or periodicallytransmitted, such as when activated by a sensor device.

As a pallet of products 814 is moved (e.g., by a forklift 816 or othersuitable transport means), the products move within the read range ofthe third RFID R/W reader 806. RFID tags associated with respectiveproducts, a few of which are illustrated at 818, are activated by thecorresponding emitted signal 812, and respond via respective returnsignals 820 communicated to the third RFID R/W device 806. As theforklift 816 and associated pallet of products 814 move through theenvironment, the products enter the range of the other RFID R/W devices(802 and 804), and the associated return signals will be transmitted ina similar manner. As the pallet of products 814 is moving, the RFID tagsare constantly activated (for passive devices) and providing information(for both passive and active) concerning at least one parameterassociated with the RFID R/W device (e.g., signal strength, origin, . .. ) and/or operating conditions.

While FIG. 8 illustrates products being moved by a truck, it will beappreciated that the invention works equally well in other applicationssuch as a conveyor line, manual movement of goods, etc. In addition,products can be located in a plurality of locations and do not have tobe moved as a single unit of products.

FIG. 9 illustrates a methodology 900 for optimizing performance of anRFID system. While, for purposes of simplicity of explanation, the oneor more methodologies shown herein, e.g., in the form of a flow chart orflow diagram, are shown and described as a series of acts, it is to beunderstood and appreciated that the subject invention is not limited bythe order of acts, as some acts may, in accordance with the invention,occur in a different order and/or concurrently with other acts from thatshown and described herein. For example, those skilled in the art willunderstand and appreciate that a methodology could alternatively berepresented as a series of interrelated states or events, such as in astate diagram. Moreover, not all illustrated acts may be required toimplement a methodology in accordance with the invention.

The method starts at 902 when a signal is received by an RFID tag from,for example, an RFID (R/W) component. The signal can be broadcast to aplurality of RFID tags continuously, intermittently, or periodicallydepending on the system requirements. For example, the signal may bebroadcast once every five seconds requesting information from RFIDtag(s) that may have received the signal.

At 904, the received signal is analyzed by the RFID tag. A magneticfield can be mapped based upon the strength of the signal, wherein aweak signal indicates the RFID R/W device and RFID tag are locatedfarther apart and/or there is some obstruction blocking or interferingwith the magnetic field. The signal strength is obtained by measuringthe voltage received from the RFID R/W component. At 906, the measuredvoltage and/or data representative of the voltage is added, as extrainformation, to the end of the tag data that is sent to the RFID R/Wcomponent. The RFID tag can also obtain other information, such assignal origin and/or operating conditions at 908. This information isincluded in the tag data, at 910, generally at the end, and is extrainformation. At 912, the RFID tag transmits the tag data and any extrainformation to the RFID R/W component.

With reference now to FIG. 10, illustrated is a methodology 1000 forutilizing an intelligent RFID tag to obtain signal strength andenvironment information. The method begins at 1002 where a signal issent to one or more intelligent RFID tags. The signal generallyspecifies a range of tags that should respond to the signal. The tagswithin the requested range respond at 1004. If multiple tags respond, asmaller range is specified until only one tag responds and can beidentified. The response from the one or more tags includes tag data,signal or field strength measurement, and optional other information,such as temperature, humidity, shock, etc. The detection component sendsanother signal at 1002 looking for additional tags until no tagsrespond. The signal or field strength of the tag response is obtained,at 1006, by measuring the voltage received from the tag. Thisinformation can be utilized to map the magnetic field.

The methodology continues at 1008 where, based upon the results of themapping of the magnetic field, an adjustment of the signal strength,antenna, or both is performed. The adjustment can be a recommendation ofa physical adjustment to the antenna, whereby a controller associatedwith the RFID R/W device outputs a recommended action to a user. Theadjustment can be autonomous whereby the system electronically adjuststhe signal strength without any user interface. After any adjustmentsare made and/or periodically, the method can return to 1002 and repeatsthe methodology as many times as necessary to achieve a predeterminedsystem accuracy and/or to continually monitor system accuracy.

Referring now to FIG. 11, there is illustrated a block diagram of acomputer operable to process signal strength data and generate a fieldmapping in accordance with the subject invention. In order to provideadditional context for various aspects of the subject invention, FIG. 11and the following discussion are intended to provide a brief, generaldescription of a suitable computing environment 1100 in which thevarious aspects of the invention can be implemented. While the inventionhas been described above in the general context of computer-executableinstructions that may run on one or more computers, those skilled in theart will recognize that the invention also can be implemented incombination with other program modules and/or as a combination ofhardware and software.

Generally, program modules include routines, programs, components, datastructures, etc., that perform particular tasks or implement particularabstract data types. Moreover, those skilled in the art will appreciatethat the inventive methods can be practiced with other computer systemconfigurations, including single-processor or multiprocessor computersystems, minicomputers, mainframe computers, as well as personalcomputers, hand-held computing devices, microprocessor-based orprogrammable consumer electronics, and the like, each of which can beoperatively coupled to one or more associated devices.

The illustrated aspects of the invention may also be practiced indistributed computing environments where certain tasks are performed byremote processing devices that are linked through a communicationsnetwork. In a distributed computing environment, program modules can belocated in both local and remote memory storage devices.

A computer typically includes a variety of computer-readable media.Computer-readable media can be any available media that can be accessedby the computer and includes both volatile and non-volatile media,removable and non-removable media. By way of example, and notlimitation, computer-readable media can comprise computer storage mediaand communication media. Computer storage media includes both volatileand non-volatile, removable and non-removable media implemented in anymethod or technology for storage of information such ascomputer-readable instructions, data structures, program modules, orother data. Computer storage media includes, but is not limited to, RAM,ROM, EEPROM, flash memory or other memory technology, CD-ROM, digitalvideo disk (DVD) or other optical disk storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium which can be used to store the desired informationand which can be accessed by the computer.

Communication media typically embodies computer-readable instructions,data structures, program modules, or other data in a modulated datasignal such as a carrier wave or other transport mechanism, and includesany information delivery media. The term “modulated data signal” means asignal that has one or more of its characteristics set or changed insuch a manner as to encode information in the signal. By way of example,and not limitation, communication media includes wired media such as awired network or direct-wired connection, and wireless media such asacoustic, RF, infrared and other wireless media. Combinations of the anyof the above should also be included within the scope ofcomputer-readable media.

With reference again to FIG. 11, the exemplary environment 1100 forimplementing various aspects of the invention includes a computer 1102,the computer 1102 including a processing unit 1104, a system memory 1106and a system bus 1108. The system bus 1108 couples system componentsincluding, but not limited to, the system memory 1106 to the processingunit 1104. The processing unit 1104 can be any of various commerciallyavailable processors. Dual microprocessors and other multi-processorarchitectures may also be employed as the processing unit 1104.

The system bus 1108 can be any of several types of bus structure thatmay further interconnect to a memory bus (with or without a memorycontroller), a peripheral bus, and a local bus using any of a variety ofcommercially available bus architectures. The system memory 1106includes read-only memory (ROM) 1110 and random access memory (RAM)1112. A basic input/output system (BIOS) is stored in a non-volatilememory 1110 such as ROM, EPROM, EEPROM, which BIOS contains the basicroutines that help to transfer information between elements within thecomputer 1102, such as during start-up. The RAM 1112 can also include ahigh-speed RAM such as static RAM for caching data.

The computer 1102 further includes an internal hard disk drive (HDD)1114 (e.g., EIDE, SATA), which internal hard disk drive 1114 may also beconfigured for external use in a suitable chassis (not shown), amagnetic floppy disk drive (FDD) 1116, (e.g., to read from or write to aremovable diskette 1118) and an optical disk drive 1120, (e.g., readinga CD-ROM disk 1122 or, to read from or write to other high capacityoptical media such as the DVD). The hard disk drive 1114, magnetic diskdrive 1116, and optical disk drive 1120 can be connected to the systembus 1108 by a hard disk drive interface 1124, a magnetic disk driveinterface 1126 and an optical drive interface 1128, respectively. Theinterface 1124 for external drive implementations includes at least oneor both of Universal Serial Bus (USB) and IEEE 1394 interfacetechnologies. Other external drive connection technologies are withincontemplation of the subject invention.

The drives and their associated computer-readable media providenonvolatile storage of data, data structures, computer-executableinstructions, and so forth. For the computer 1102, the drives and mediaaccommodate the storage of any data in a suitable digital format.Although the description of computer-readable media above refers to aHDD, a removable magnetic diskette, and a removable optical media suchas a CD or DVD, it should be appreciated by those skilled in the artthat other types of media which are readable by a computer, such as zipdrives, magnetic cassettes, flash memory cards, cartridges, and thelike, may also be used in the exemplary operating environment, andfurther, that any such media may contain computer-executableinstructions for performing the methods of the invention.

A number of program modules can be stored in the drives and RAM 1112,including an operating system 1130, one or more application programs1132, other program modules 1134, and program data 1136. All or portionsof the operating system, applications, modules, and/or data can also becached in the RAM 1112. It is appreciated that the invention can beimplemented with various commercially available operating systems orcombinations of operating systems.

A user can enter commands and information into the computer 1102 throughone or more wired/wireless input devices, e.g., a keyboard 1138 and apointing device, such as a mouse 1140. Other input devices (not shown)may include a microphone, an IR remote control, a joystick, a game pad,a stylus pen, touch screen, or the like. These and other input devicesare often connected to the processing unit 1104 through an input deviceinterface 1142 that is coupled to the system bus 1108, but can beconnected by other interfaces, such as a parallel port, an IEEE 1394serial port, a game port, a USB port, an IR interface, etc.

A monitor 1144 or other type of display device is also connected to thesystem bus 1108 via an interface, such as a video adapter 1146. Inaddition to the monitor 1144, a computer typically includes otherperipheral output devices (not shown), such as speakers, printers, etc.

The computer 1102 may operate in a networked environment using logicalconnections via wired and/or wireless communications to one or moreremote computers, such as a remote computer(s) 1148. The remotecomputer(s) 1148 can be a workstation, a server computer, a router, apersonal computer, portable computer, microprocessor-based entertainmentappliance, a peer device, or other common network node, and typicallyincludes many or all of the elements described relative to the computer1102, although, for purposes of brevity, only a memory/storage device1150 is illustrated. The logical connections depicted includewired/wireless connectivity to a local area network (LAN) 1152 and/orlarger networks, e.g., a wide area network (WAN) 1154. Such LAN and WANnetworking environments are commonplace in offices and companies, andfacilitate enterprise-wide computer networks, such as intranets, all ofwhich may connect to a global communications network, e.g., theInternet.

When used in a LAN networking environment, the computer 1102 isconnected to the local network 1152 through a wired and/or wirelesscommunication network interface or adapter 1156. The adaptor 1156 mayfacilitate wired or wireless communication to the LAN 1152, which mayalso include a wireless access point disposed thereon for communicatingwith the wireless adaptor 1156.

When used in a WAN networking environment, the computer 1102 can includea modem 1158, or is connected to a communications server on the WAN1154, or has other means for establishing communications over the WAN1154, such as by way of the Internet. The modem 1158, which can beinternal or external and a wired or wireless device, is connected to thesystem bus 1108 via the serial port interface 1142. In a networkedenvironment, program modules depicted relative to the computer 1102, orportions thereof, can be stored in the remote memory/storage device1150. It will be appreciated that the network connections shown areexemplary and other means of establishing a communications link betweenthe computers can be used.

The computer 1102 is operable to communicate with any wireless devicesor entities operatively disposed in wireless communication, e.g., aprinter, scanner, desktop and/or portable computer, portable dataassistant, communications satellite, any piece of equipment or locationassociated with a wirelessly detectable tag (e.g., a kiosk, news stand,restroom), and telephone. This includes at least Wi-Fi and Bluetooth™wireless technologies. Thus, the communication can be a predefinedstructure as with a conventional network or simply an ad hoccommunication between at least two devices.

Wi-Fi, or Wireless Fidelity, allows connection to the Internet from acouch at home, a bed in a hotel room, or a conference room at work,without wires. Wi-Fi is a wireless technology similar to that used in acell phone that enables such devices, e.g., computers, to send andreceive data indoors and out; anywhere within the range of a basestation. Wi-Fi networks use radio technologies called IEEE 802.11 (a, b,g, etc.) to provide secure, reliable, fast wireless connectivity. AWi-Fi network can be used to connect computers to each other, to theInternet, and to wired networks (which use IEEE 802.3 or Ethernet).Wi-Fi networks operate in the unlicensed 2.4 and 5 GHz radio bands, atan 11 Mbps (802.11a) or 54 Mbps (802.11b) data rate, for example, orwith products that contain both bands (dual band), so the networks canprovide real-world performance similar to the basic 10BaseT wiredEthernet networks used in many offices.

Referring now to FIG. 12, there is illustrated a schematic block diagramof an exemplary computing environment 1200 that facilitates magneticfield mapping in accordance with the subject invention. The system 1200includes one or more client(s) 1202. The client(s) 1202 can be hardwareand/or software (e.g., threads, processes, computing devices). Theclient(s) 1202 can house cookie(s) and/or associated contextualinformation by employing the invention, for example.

The system 1200 also includes one or more server(s) 1204. The server(s)1204 can also be hardware and/or software (e.g., threads, processes,computing devices). The servers 1204 can house threads to performtransformations by employing the invention, for example. One possiblecommunication between a client 1202 and a server 1204 can be in the formof a data packet adapted to be transmitted between two or more computerprocesses. The data packet may include a cookie and/or associatedcontextual information, for example. The system 1200 includes acommunication framework 1206 (e.g., a global communication network suchas the Internet) that can be employed to facilitate communicationsbetween the client(s) 1202 and the server(s) 1204.

Communications can be facilitated via a wired (including optical fiber)and/or wireless technology. The client(s) 1202 are operatively connectedto one or more client data store(s) 1208 that can be employed to storeinformation local to the client(s) 1202 (e.g., cookie(s) and/orassociated contextual information). Similarly, the server(s) 1204 areoperatively connected to one or more server data store(s) 1210 that canbe employed to store information local to the servers 1204.

The framework 1206 can also include a subnetwork 1212, for example, thatcan be implemented as in an assembly line environment. The subnetwork1212 can have disposed thereon as nodes, a controller 1214 (e.g., a PLC)that controls a reader module 1216 and a reader/writer module 1218 bothof which can read RFID tags, and the latter of which can write data tothe RFID tags. The controller 1214, reader module 1216 and reader/writermodule 1218 can be provided in a rack configuration at selectedlocations. Alternatively or in combination therewith, the subnetwork1212 can also include a second reader module 1220 as a wired or wirelessnode (or client) that is positioned (fixed or mobile) to read RFID tags,as needed. Similarly, the subnetwork 1212 can also support areader/writer module 1222 as a wired and/or wireless client node forreading and writing data and signals to RFID tags that come within acoverage area.

What has been described above includes examples of the invention. It is,of course, not possible to describe every conceivable combination ofcomponents or methodologies for purposes of describing the subjectinvention, but one of ordinary skill in the art may recognize that manyfurther combinations and permutations of the invention are possible.Accordingly, the invention is intended to embrace all such alterations,modifications and variations that fall within the spirit and scope ofthe appended claims. Furthermore, to the extent that the term “includes”is used in either the detailed description or the claims, such term isintended to be inclusive in a manner similar to the term “comprising” as“comprising” is interpreted when employed as a transitional word in aclaim.

1. A method, comprising: transporting articles within a coverage area ofa radio frequency identification (RFID) system, a subset of the articleseach having one of a plurality of RFID components physically attachedthereto; interrogating the plurality of RFID components using anactivation signal from an RFID reader; receiving, in response to theinterrogating, return signals from the plurality of RFID componentscontaining at least one ambient environmental parameter measured by therespective RFID components via environmental sensors integrated with theRFID components; determining whether the at least one ambientenvironmental parameter indicates an operating condition that adverselyaffects a received signal strength of the activation signal detected atthe respective RFID components; and adjusting an output signal strengthof the activation signal at the RFID reader based on the determining. 2.The method of claim 1, wherein receiving comprises receiving the returnsignals containing at least one of a temperature parameter, a humidityparameter, a vibration parameter, or a shock parameter.
 3. The method ofclaim 1, further comprising: receiving at the RFID reader activationsignal strength measurements measured by the plurality of RFIDcomponents; and mapping the activation signal strength measurements. 4.The method of claim 3, further comprising electronically or physicallyadjusting an antenna of the RFID reader based on the determining.
 5. Themethod of claim 3, further comprising adjusting a result of the mappingbased upon the at least one ambient environmental parameter.
 6. Themethod of claim 5, further comprising: detecting at least one of atemperature measurement or a humidity measurement as the at least oneambient environmental parameter; and estimating a degree of absorptionof the activation signal due to moisture based on the at least one ofthe temperature measurement or the humidity measurement.
 7. The methodof claim 1, further comprising mapping activation signal strengthsmeasured at the RFID components by transmitting a first instruction tothe RFID components via a first activation signal to respond if astrength of the first activation signal measured by the respective RFIDcomponents is greater than a specified first threshold.
 8. The method ofclaim 7, further comprising transmitting a second instruction to theRFID components via a second activation signal to respond if a strengthof the second activation signal measured by the respective RFIDcomponents is greater than a second threshold greater than the firstthreshold to facilitate receiving responses from a smaller number ofRFID components than responded to the first instruction.
 9. The methodof claim 1, further comprising: receiving an environmental parameter oftemperature sensed by the RFID components; and determining whether theenvironmental parameter of temperature is outside of a temperature rangeindicating a possible risk of temperature-related damage to thearticles.
 10. The method of claim 1, further comprising: receiving anenvironmental parameter of movement of the RFID components; anddetermining whether the parameter of movement is outside of a movementrange indicating an abnormal operation of at least one mechanicalcomponent that transports the articles.
 11. The method of claim 10,wherein receiving the environmental parameter of movement comprisesreceiving at least one of a vibration measurement or a shock measurementmeasured by the RFID components using the environmental sensors.
 12. Asystem, comprising: a plurality of radio frequency identification (RFID)components that measure at least one environmental parameter usingenvironmental sensors integrated with the RFID components; and an RFIDreader that interrogates the plurality of RFID components using anactivation signal, receives return signals from the RFID componentscontaining the at least one environmental parameter measured by the RFIDcomponents, and determines whether the at least one environmentalparameter indicates an operating condition that adversely affects areceived signal strength of the activation signal detected at the RFIDcomponents, wherein the RFID reader adjusts an output signal strength ofthe activation signal based on the at least one environmental parameter;and wherein the RFID reader receives via the return signal's activationsignal strength values measured by the plurality of RFID components andmaps the activation signal strength measurements to yield a receptionperformance mapping.
 13. The system of claim 12, wherein the at leastone environmental parameter is at least one of temperature, humidity,vibration, or shock.
 14. The system of claim 12, wherein the RFID readercomprises an RFID antenna that is electronically or physicallyadjustable based on the reception performance mapping.
 15. The system ofclaim 12, wherein the RFID reader modifies the reception performancemapping based upon the at least one environmental parameter.
 16. Thesystem of claim 15, wherein the RFID reader receives at least one of atemperature measurement or a humidity measurement as the at least oneenvironmental parameter and estimates a degree of absorption of theactivation signal due to moisture based on the at least one of thetemperature measurement or the humidity measurement.
 17. The system ofclaim 12, wherein the RFID reader maps activation signal strengthsmeasured at the RFID components by transmitting a first instruction tothe RFID components via a first activation signal to respond if astrength of the first activation signal measured by the respective RFIDcomponents is greater than a specified first threshold.
 18. The systemof claim 17, wherein the RFID reader transmits a second instruction tothe RFID components via a second activation signal to respond if astrength of the second activation signal measured by the respective RFIDcomponents is greater than a second threshold that is greater than thefirst threshold to facilitate receiving responses from a smaller numberof RFID components than responded to the first instruction.
 19. Thesystem of claim 12, further comprising a plurality of RFID readerantennas spaced apart to facilitate receipt of a plurality of differentactivation signal strength measurements for each of the plurality ofRFID components based on a location of the respective RFID componentsrelative to the RFID reader antennas.
 20. The system of claim 12,wherein the RFID reader receives an environmental parameter oftemperature sensed by the RFID components, and determines whether thereceived environmental parameter of temperature is outside of atemperature range indicating a possible risk of damage to objects towhich the RFID components are physically attached.
 21. The system ofclaim 12, wherein the RFID reader receives an environmental parameter ofmovement for the RFID components, and determines whether theenvironmental parameter of movement is outside of a movement rangeindicating an abnormal operation of at least one mechanical componentthat transports objects to which the RFID components are physicallyconnected.
 22. The system of claim 21, wherein the environmentalparameter of movement includes at least one of a vibration measurementor a shock measurement sensed by the RFID components using theenvironmental sensors.
 23. The system of claim 22, further comprising aconveyor for moving the objects to which the RFID components arephysically connected.
 24. An apparatus, comprising: means forinterrogating a plurality of radio frequency identification (RFID)components within a coverage area of an RFID reader antenna using anactivation signal; means for receiving, in response to theinterrogating, return signals from the plurality of RFID componentscontaining at least one environmental parameter and a received signalstrength of the activation signal measured by the respective RFIDcomponents via sensors integrated with the RFID components; means fordetermining whether the at least one environmental parameter indicatesan operating condition detrimental to the received signal strength ofthe activation signal measured at the respective RFID components; andmeans for adjusting an output strength of the activation signal based onthe at least one environmental parameter.
 25. A method, comprising:positioning a radio frequency identification (RFID) antenna of an RFIDsystem to define a coverage area; attaching a plurality of RFIDcomponents to a plurality of articles; transporting the plurality ofarticles through the coverage area; interrogating the plurality of RFIDcomponents using an interrogation signal; mapping the coverage area ofthe RFID system based upon responses received from the RFID components;and adjusting the RFID antenna to optimize the coverage area.
 26. Themethod of claim 25, further comprising: receiving signal strength valuesmeasured via signal strength processing blocks integrated within theplurality of RFID components and transmitted thereby; and mapping thecoverage area of the RFID system based upon the signal strength value.27. The method of claim 25, further comprising: receiving return signalscontaining ambient environmental parameters measured via environmentalsensors integrated within the plurality of RFID components andtransmitted thereby; and adjusting the mapped coverage area of the RFIDsystem to compensate for the received ambient environmental parameters.28. The method of claim 27, wherein receiving return signals comprisesreceiving the return signals containing an ambient environmentalparameter comprising temperature.
 29. The method of claim 27, whereinreceiving return signals comprises receiving the return signalscontaining an ambient environmental parameter comprising humidity. 30.The method of claim 29, wherein receiving return signals comprisesreceiving the return signals containing an ambient environmentalparameter further comprising temperature.
 31. The method of claim 25,further comprising: instructing the plurality of RFID components torespond if a strength of the interrogation signal measured at therespective RFID components exceeds a threshold; and receiving responsesfrom a subset of the plurality of RFID components within range of theRFID system that measured the strength of the interrogation signal asbeing above the threshold.
 32. The method of claim 31, furthercomprising repeatedly instructing the plurality of RFID components torespond if the strength of the interrogation signal exceeds aniteratively increased threshold until a number of the responses is belowa targeted value.
 33. The method of claim 25, further comprisingautomatically adjusting the RFID antenna electronically.
 34. The methodof claim 25, further comprising presenting information regarding thecoverage area for mechanical adjustment of the RFID antenna.
 35. Amethod, comprising: interrogating a radio frequency (RFID) componentattached to an article within a coverage area of an RFID system using anactivation signal; receiving a return signal transmitted by the RFIDcomponent in response to the interrogating, the return signal containinga temperature value measured by the RFID component using environmentalsensors integrated therein; determining whether the temperature valueindicates an operating condition that adversely affects a receivedsignal strength of the activation signal detected at the RFID component;adjusting an output strength of the activation signal based on thetemperature value; receiving, via the return signal, an activationsignal strength value measured by the RFID component using a signalstrength processing block integrated therein; and mapping the activationsignal strength measurement to yield a reception performance mapping.36. A method, comprising: attaching a radio frequency identification(RFID) component to an article; conveying the article through a coveragearea of an RFID reader; interrogating the RFID component; receiving, inresponse to the interrogating, a return signal from the RFID componentcontaining a movement parameter measured by a movement sensor integratedwithin the RFID component; and determining an operating condition of amechanism performing the conveying based upon the movement parameter.37. The method of claim 36, wherein receiving comprises receiving thereturn signal containing a vibration parameter measured by a vibrationsensor integrated within the RFID component.
 38. The method of claim 36,wherein receiving comprises receiving the return signal containing ashock parameter measured by a shock sensor integrated within the RFIDcomponent.